His stinginess upsets me sir! (5)

I believe the answer is:

miser

I'm a little stuck... Click here to teach me more about this clue!

'his stinginess' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.

'upsets me sir' is the wordplay.
'upsets' indicates an anagram.
'me'+'sir'='mesir'
'mesir' with letters rearranged gives 'MISER'.

Can you help me to learn more?

(Other definitions for miser that I've seen before include "He's close" , "One of the people who spend least" , "Niggard" , "screw" , "One such as Scrooge" .)

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.